Venkat
The majority of undergraduate medical degrees require Chemistry — such as a score of at least 5 in Chemistry SL or 4 in Chemistry HL. Some universities also recommend Biology, although I don't believe it's a formal requirement (I may be wrong on this).
Undergraduate medicine is very competitive. If she doesn't get in then she may wish to complete a different undergraduate degree first and use that to enter graduate-entry medicine. Taking SL Maths will allow a broader range of undergraduate degrees to pick from — it's a common subject requirement for biomedical degrees and some science degrees.
